A liquid crystal display device typified by a liquid crystal display panel, a liquid crystal display module and so forth utilizes optical anisotropy, dielectric anisotropy and so forth of a liquid crystal compound (generically meaning a compound having a liquid crystal phase such as a nematic phase or a smectic phase, and a compound having no liquid crystal phase but being useful as a component of a liquid crystal composition, according to the invention). As an operating mode of the liquid crystal display device, such a variety of modes are known as a phase change (PC) mode, a twisted nematic (TN) mode, a super twisted nematic (STN) mode, a bistable twisted nematic (BTN) mode, an electrically controlled birefringence (ECB) mode, an optically compensated bend (OCB) mode, an in-plane switching (IPS) mode, a vertical alignment (VA) mode and a polymer sustained alignment (PSA) mode.
In the operating modes, the ECB mode, the IPS mode, the VA mode and so forth utilize homeotropic orientation of liquid crystal molecules. In particular, the IPS mode and the VA mode are known to allow improvement in a limited viewing angle as a disadvantage of a conventionally applied display mode such as the TN mode and the STN mode.
Then, as a component of a liquid crystal composition that has a negative dielectric anisotropy and can be used in the liquid crystal display devices according to the operating modes, a research has been so far conducted for many liquid crystal compounds having propyl ether as a bonding group and many liquid crystal compounds in which hydrogen on propyl ether is replaced by fluorine, oxygen or a methyl group. However, such compounds do not have a large negative dielectric anisotropy really.
For example, an examination has been made for compound (A) having propyl ether as a bonding group (see Patent literature No. 1). However, such a compound does not have a large negative dielectric anisotropy really.
Moreover, an examination has been made for compound (B) having a bonding group in which hydrogen on propyl ether is replaced by fluorine (see Patent literature No. 2). However, compound (B) does not have a large negative dielectric anisotropy really.
Moreover, an examination has been made for compound (C) having a bonding group in which hydrogen on propyl ether is replaced by oxygen (see Patent literature No. 3). However, compound (C) does not have a large negative dielectric anisotropy really.
Furthermore, an examination has been made for compound (D) having a bonding group in which hydrogen on propyl ether is replaced by fluorine and oxygen (see Patent literature No. 4). However, compound (D) does not have a large negative dielectric anisotropy really.
Furthermore, an examination has been made for compound (E) having a bonding group in which hydrogen on propyl ether is replaced by a methyl group (see Patent literature No. 5). However, compound (E) does not have a large negative dielectric anisotropy really.
